Checklist Multi Throttle Tuning Method

This guide shows the recommend method to configure a boosted or naturally aspirated engine that contains Individual Throttle Bodies for each cylinder. Clicking each item (M1 Tune v1.5 only) will select the item and allow you to enter the required information. Once an item has been selected the help, for that item, can be displayed by hitting the F1 key.

Setup

1. Turn off all Engine Efficiency table axes and set the remaining site to 100%. This table will not be adjusted.
2. Set Engine Load Normalised Mode to Normal.
3. Set Engine Efficiency Mode to Manifold Air Density.
4. Set Inlet Manifold Pressure Mode to Estimate.
5. Set Inlet Manifold Pressure Sensor Resource to Not in Use.
6. For a boosted engine:
   1. Setup and calibrate Boost Pressure Sensor.
   2. Set Inlet Manifold Pressure Estimate Mode to Boost Pressure Relative.
   3. Set Fuel Injector Primary Location and Fuel Injector Secondary Location to Before Throttle Boost Referenced. Use this setting even if the injectors are positioned after the throttles.
7. For a naturally aspirated engine:
   1. Setup and calibrate Airbox Pressure Sensor.
   2. Set Inlet Manifold Pressure Estimate Mode to Ambient Pressure Relative.
   3. Set Fuel Injector Primary Location and Fuel Injector Secondary Location to Before Throttle Airbox Referenced. Use this setting even if the injectors are positioned after the throttles.
8. Set Fuel Timing Primary and Fuel Timing Secondary with an End of Injection earlier than ~380deg BTDC (before the inlet valve opens) for light to medium load. For higher load, the injection time can be set as needed. This will assist with the accuracy of injector differential pressure value.
9. Initially set the entire Engine Efficiency Boost Pressure Compensation table and Engine Efficiency Airbox Pressure Compensation tables to 0% trim

Tuning Boosted Engine

With this method the Inlet Manifold Pressure Estimate Main table is the primary fuel tuning table.

1. If the engine has not been tuned, set a low Boost Aim pressure to perform a safe initial tune, otherwise go to step 3.
2. Tune the Inlet Manifold Pressure Estimate Main table until the Exhaust Lambda matches the Fuel Mixture Aim for each site. This is only an initial tune and doesn't need to be detailed. Note: values greater than 100% are possible.
3. Once the engine is tuned at the low boost pressure (see step 1), set the Boost Aim Pressure to the maximum intended boost pressure. This is so the tuning is as accurate as possible for the highest (most critical) load.
4. Set the Engine Efficiency Boost Pressure Compensation to 0% trim at the boost pressure set in step 4.
5. Tune the Inlet Manifold Pressure Estimate Main table until the Exhaust Lambda matches the Fuel Mixture Aim for each site. Note: values greater than 100% are possible.
6. Lower the Boost Aim pressure.
7. At 100% throttle, alter the Engine Efficiency Boost Pressure Compensation table to correct the fuelling. Typically, 100% throttle is the most important point to be perfectly correct. Leave the Engine Efficiency Boost Pressure Compensation at the boost pressure from in step 6 at 0% trim.
8. Repeat steps 6 and 7 for all boost pressures between the desired highest and lowest boost pressures

Additional checks for tuning adjustments:

• In conditions with low boost and high throttle the boost might not match the tuned boost pressure. For example, when the throttle is opened quickly and the turbo speed is low. Be sure to check the tuning in these conditions and if needed, adjust the Engine Efficiency Boost Pressure Compensation table.
• Many systems other than fuelling use the Inlet Manifold Pressure value. With this method the value is no longer directly derived from a sensor, however the calculated value has similar behaviour and scale to inlet manifold pressure sensed on a common plenum engine. In many subsystems using the Inlet Manifold Pressure value, the calculated value may need adjusting slightly. In some systems the accuracy may be sufficient and no adjustment is necessary. These systems should only be adjusted after tuning the fuelling since this tuning method affects the result of the Inlet Manifold Pressure value. The resulting Inlet Manifold Pressure value may be higher than Boost Pressure in some conditions.
• If the Camshaft, Camshaft Position, Intake, Exhaust or any other parameter that affect the volumetric efficiency of the engine are changed, repeat all steps.

Tuning Naturally Aspirated Engine

With this method the Inlet Manifold Pressure Estimate Main table is the primary fuel tuning table. The table result value becomes the percentage of the cylinders displacement volume for air at the current Airbox Pressure and Temperature, inducted into the cylinder for the given engine speed and throttle position.

1. At a constant Airbox Pressure, tune the Inlet Manifold Pressure Estimate Main table until the Exhaust Lambda matches the Fuel Mixture Aim for each site. Note: values greater than 100% are possible.
2. If using a dynamometer with a controlled air intake, adjust the Ambient Pressure to change the Airbox Pressure and use the Engine Efficiency Airbox Pressure Compensation table to correct the fuelling. Leaving the Engine Efficiency Airbox Pressure Compensation at the Airbox Pressure from in step 2 at 0% trim.

Additional checks for tuning adjustments:

• Many systems other than fuelling use the Inlet Manifold Pressure value. With this method the value is no longer directly derived from a sensor, however the calculated value has similar behaviour and scale to inlet manifold pressure sensed on a common plenum engine. In many subsystems using the Inlet Manifold Pressure value, the calculated value may need adjusting slightly. In some systems the accuracy may be sufficient and no adjustment is necessary. These systems should only be adjusted after tuning the fuelling since this tuning method affects the result of the Inlet Manifold Pressure value.
• If the Camshaft, Camshaft Position, Intake, Exhaust or any other parameter that affect the volumetric efficiency of the engine are changed, repeat all steps.